Sounds like there's something seriously wrong with the 32g card. The 64g card won't boot because it didn't have ML on it.
I don't know the minutiae, but I had to repeat the install procedure for each individual SD card so they would all work with ML.
If you depower the camera completely, and remove any cards then turn it on, it should revert to normal and you can start again with the 64g

Hi,
;just a few quick ideas. Try the following at your own risk. I have the Canon 60d.
First, make sure you have the correct Canon Firmware installed for the version of ML you are trying to install. I had to update my Canon Firmware before continuing to install version 2.3. There are a few videos on Youtube that show you how to install Ml on your 60d.. I have Version 2.3 installed on my 60d using 16GB and 32GB Sandisk SD cards. So basically once you have the correct Canon firmware version installed next is to format your SD cards. I did this in the camera. Then I downloaded the ML zip file and unzipped the ML files. I then copied all unzipped files to the Root directory of the SD card.. I then put the SD card back into my camera. I next set the Camera in to "M" (manual mode). This is important! Then I went to the menu where it has update firmware. Select update firmware as thought you are going to update the Canon firmware again. Once ML says update Successful then turn off camera and turn camera back on again. Then everything should be installed. You need to repeat this procedure on every SD card you want to use with the camera.
There is one video from "cadwickpaulpost" that shows you how to install ML on Youtube except he does not say to update the Canon firmware first. Imho slow down and double check that you did not miss a step. Also make sure you have a fully charged battery installed before you start.
As for the cards saying full I am not sure. Check the cards in your computer and see what the computer says as to whether there is information on the card or any hidden file and the amount of GB used on the card if any. If the card reads 0kb free but does not show and files on the card then mybe there are some hidden files on the card. if you can format the SD card in your computer try that and then try formatting the SD card in your camera again.. Maybe someone else will be of more help on this issue.

Hi,
;just a few quick ideas. Try the following at your own risk. I have the Canon 60d.
First, make sure you have the correct Canon Firmware installed for the version of ML you are trying to install. I had to update my Canon Firmware before continuing to install version 2.3. There are a few videos on Youtube that show you how to install Ml on your 60d.. I have Version 2.3 installed on my 60d using 16GB and 32GB Sandisk SD cards. So basically once you have the correct Canon firmware version installed next is to format your SD cards. I did this in the camera. Then I downloaded the ML zip file and unzipped the ML files. I then copied all unzipped files to the Root directory of the SD card.. I then put the SD card back into my camera. I next set the Camera in to "M" (manual mode). This is important! Then I went to the menu where it has update firmware. Select update firmware as thought you are going to update the Canon firmware again. Once ML says update Successful then turn off camera and turn camera back on again. Then everything should be installed. You need to repeat this procedure on every SD card you want to use with the camera.